AirHint found the following cheapest return flights from Ontario (ONT) to San Juan (SJU) in January 2026 (see full year).

Return flights

11 Jan - 25 Jan	Southwest Airlines
18 Jan - 25 Jan	Southwest Airlines
09 Jan - 13 Jan	Southwest Airlines
08 Jan - 12 Jan	Southwest Airlines
04 Jan - 11 Jan	Southwest Airlines
11 Jan - 18 Jan	Southwest Airlines
04 Jan - 18 Jan	Southwest Airlines
02 Jan - 06 Jan	Southwest Airlines

Also check the deals for one-way flights from Ontario to San Juan in January.

The deals are updated regularly. The prices may go up as tickets are purchased by other travellers. Only the cheapest flights are offered. Select a price to book and secure these cheap prices.

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Cheapest return flights from Ontario to San Juan in January from $565

Return flights